Sure, CS3 gives the user more control, but to a pro, time is money and that level of control is not necessary for every purpose. You may see picture noise on screen but if that picture noise means better resolution and does not show up in a print, does it really matter if the end result is printing. Selling an art piece to a high level magazine or gallery is different from public relations work for a small folder. Work for the general public is different from work submitted to an art director.
A pro who is a true business person works on several quality levels related to the individual projects. This also allows varied pricing and flexibility. It is rather ridiculous in the worst case scenario to spend time on CS3 edits and modifications that won't be noticed when the project could be completed in half the time with a greater profit margin using Paint Shop Pro and plug-ins.
For some projects, all that may be needed is batch processing in DXO Optics Pro. For others perhaps PaintShop Pro and Plug-ins are the answer. For the final level, CS3 is needed. The question however for some pros is...how much of my work really demands the use of CS3?
Complicating things further you need to realize that a big variable is the postprocessing skills of the photographer. I can't remember the photo mag but one indicated that the difference in output from a highly skilled postprocessor using the latest version of PaintShop Pro Photo X2 and Photoshop CS3 was minimal.
To a pro, speed trumps output unless there is a a noticeable difference that makes the extra time worth it in terms of profit or reputation. The decision is an individual one, since not everyone has the same level of postprocessing skills.
skieur